Unlike conventional random access memory (RAM) chip technologies, magnetic RAM (MRAM) does not store data as electric charge, but instead stores data by magnetic polarization of storage elements. Typically, storage elements are formed from two ferromagnetic layers separated by a tunneling layer. One of the ferromagnetic layers has at least one pinned magnetic polarization (or fixed layer) set to a particular polarity. The magnetic polarity of the other ferromagnetic layer (or free layer) is altered to represent either a “1” (i.e., anti-parallel polarity to the fixed layer) or “0” (i.e., parallel polarity to the fixed layer). One device having a fixed layer, a tunneling layer, and a free layer is a magnetic tunnel junction (MTJ). The electrical resistance of an MTJ is dependent on the magnetic polarity of the free layer compared to the magnetic polarity of the fixed layer. A memory device such as MRAM may be built from an array of individually addressable MTJs.
Conventionally, an MTJ contacts a first conductive line through a bottom electrode. The MTJ is positioned on the bottom electrode in a location distanced from the first conductive line. As explained above, the MTJ is formed by a MTJ material stack including a fixed layer that is positioned on the bottom electrode. A top electrode is formed on the free layer of the MTJ material stack. A critical challenge in MRAM technology is the patterning of the various layers forming the MTJ. Avoiding shorting around the MTJ requires the use of several dielectric and conductive layers. Conventional processing to form the MJT necessitates the use of several lithography masks and may be time-consuming.
Accordingly, it is desirable to provide integrated circuits and methods for fabricating integrated circuits that include MTJs that allow for more time-efficient manufacture. In addition, it is desirable to provide methods for fabricating integrated circuits that form an embedded bottom electrode structure for later connection to an MTJ structure in a maskless process. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.